Update duration when demuxed packets exceed known duration.

media/filters/ffmpeg_demuxer.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Implements the Demuxer interface using FFmpeg's libavformat.  At this time
 // will support demuxing any audio/video format thrown at it.  The streams
 // output mime types audio/x-ffmpeg and video/x-ffmpeg and include an integer
 // key FFmpegCodecID which contains the CodecID enumeration value.  The CodecIDs
 // can be used to create and initialize the corresponding FFmpeg decoder.
 //
@@ skipping 336 matching lines @@
   // The Time associated with timestamp 0. Set to a null
   // time if the file doesn't have an association to Time.
   base::Time timeline_offset_;
 
   // Whether text streams have been enabled for this demuxer.
   bool text_enabled_;
 
   // Set if we know duration of the audio stream. Used when processing end of
   // stream -- at this moment we definitely know duration.
   bool duration_known_;
+  base::TimeDelta duration_;
 
   // FFmpegURLProtocol implementation and corresponding glue bits.
   std::unique_ptr<BlockingUrlProtocol> url_protocol_;
   std::unique_ptr<FFmpegGlue> glue_;
 
   const EncryptedMediaInitDataCB encrypted_media_init_data_cb_;
 
   const MediaTracksUpdatedCB media_tracks_updated_cb_;
 
   std::map<MediaTrack::Id, DemuxerStream*> track_id_to_demux_stream_map_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtr<FFmpegDemuxer> weak_this_;
   base::WeakPtrFactory<FFmpegDemuxer> cancel_pending_seek_factory_;
   base::WeakPtrFactory<FFmpegDemuxer> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_DEMUXER_H_